In a new study, girls who walked to school did better on tests than girls who got there by car. But lazy students take heart: caffeine and sugar also up test scores.

The first study, conducted in Spain, found that girls who walked or biked to school did significantly better on "tests of cognitive function" than girls who got driven — and girls whose "active commutes" were longer than 15 minutes had an even bigger performance boost. According to Reuters, the study authors aren't sure why morning activity helps, but Dr. Francois Trudeau (who wasn't involved with the study) says a walk to school "may be a good period to start thinking about the school day." It's also not clear why the walk only benefits girls, not boys. Study authors say it's possible that boys get more overall exercise than girls, so the commute doesn't matter as much, or that exercise just impacts the sexes in different ways.

But walking to school isn't always possible. Luckily, there's another way to boost test scores: drink a whole bunch of caffeine and sugar. In another study, 18-25-year-olds dosed with caffeine or glucose performed better on a test of reaction time than a control group who just drank water. Caffeine plus glucose was even more of a miracle drug, boosting not just reaction time but also attention, manual dexterity, and memory — MSNBC's Diane Mapes writes that "the coffee-sugar combination boosted the effects of both substances, making the test subjects' brains more efficient." So basically, if you can't get teenagers to get up early, eat a wholesome breakfast, and walk to school, just hand them a can of Red Bull, because that is totally brain food.